Various types of automatic container filling machines are employed in industry to transfer bulk liquid to individual containers such as bottles, vials, ampoules, and disposable cartridges. In the pharmaceutical industry, the practice of filling small containers with a unit dose of a parenteral drug formulation for ease in dispensing, may also involve the step of flushing the containers with an inert gas, typically nitrogen, immediately prior to filling (U.S. Pat. No. 3,670,786). In either situation, whether conveying a gas or a liquid to the small container, the conduit attached to the automatic filling apparatus commonly referred to as the fill needle, is synchronized with the container feed assembly in such manner that either the needle or the individual containers reciprocate vertically so that the liquid fill or gas flush is initially introduced at the bottom of the container and completed on the reverse stroke.
The hollow fill needle is sometimes broken or bent during the verticle reciprocation stage, when it strikes the lip of an improperly seated container. Under normal usage, the front edge of the needle gradually becomes worn and burred from contact with the containers being filled. Repair of the needle requires removal of material securing the needle to the apparatus holder. Conventionally silver solder is applied at the back ends of the needle holder and at the point the needle nozzle extends from the holder at the front, to restrict bending or movement. The apparatus fitting or holder is then polished and reassembled with a new needle and the entire assembly is sterilized prior to reinsertion in the filling apparatus. Even where the used needle can be refitted in the apparatus fitting, each needle can be used at most 2 or 3 times before it is too short to properly fill the containers. Usually a needle is used once and discarded.